442 DESCRIPTION OF SOME SPECIES OF MILK BACTERIA 



Staining reaction — Ordinary aniline 

 dyes. 



Biology : cultural characters {includ- 

 ing biochemical features). 



Bouillon— Abundant growth and 

 pellicle on surface. 



Gelatine plates and tubes — 

 Smooth, shining, white colonies. 

 Slight needle growth in stab- 

 culture, with abundant white sur- 

 face growth which becomes much 

 raised. 



Agar plates and tubes; potato — 

 Not characteristic ; a white shining 

 layer. 



Milk — Becomes acid but does 

 not curdle. It is soon rendered 

 extremely slimy and can be drawn 

 out into long threads. Sometimes 

 coagulates, with production of 

 butyric acid. 



Aerobic. 



Non-pathogenic. 



MIST BACILLUS (Moeller). 



Source and habitat — Manure of horses, 

 cows, etc., thence to milk. 



Morphology — Rods ; i to 4 m long, 

 0-2 to -4 /i broad; often in masses, 

 or at angles ; variable forms, fila- 

 ments ; on blood serum, short and 

 grouped at angles, also "cocco- 

 thrix " forms ; on gelatine, thicker ; 

 in bouillon, filaments. 



Staining reaction — Acid-fast ; Ziehl- 

 Neelsen ; take Gram with difficulty ; 

 Czaplewski's method. 



Motility — Absent. 



Biology: cultural characters {includ- 

 ing biochemical features) — Best 

 temperature 37° C, on all usual 

 media ; slow growth at room tem- 

 perature. 



Bouillon — Abundant growth in 

 2 days, turbidity, yellow deposit, 

 later a pellicle, adherent to sides of 



tube. Growth better in glycerine 

 bouillon. 



Gelatine plates and tubes — 

 Growth best in depth ; very little 

 surface growth. No liquefaction. 



Agar — Grows well in 48 hours, 

 isolated colonies, slightly raised, 

 eventually thick ; at first grey- 

 white, and later a chamois colour ; 

 better growth and more coloration 

 in glycerine-agar. 



Milk — Becomes acid in 4 to 5 

 days ; sometimes coagulation 

 occurs ; red - yellow colour pro- 

 duced in pellicle. 



Blood serum — Growth along the 

 needle track ; yellow, not luxuriant. 



Aerobic. 



Pathogenesis — Similar to 

 Timothy grass bacillus. 



OIDIUM LACTIS. 



Source and habitat — Sour milk. 



Morphology ; forms and dimensions — 

 Fruit-hyphas simple, erect and 

 colourless, bearing at their ends a 

 series or chain of conidia. The 

 conidia germinating into filaments 

 of varying length, which by sub- 

 division form septate mycelial 

 hyphae. These in their branching 

 give rise to spores or conidia. 



Staining reaction — Stains well with 

 ordinary aniline stains. 



Spore formation — Spores in form of 



short cylinders. 

 Biology : cultural characters. 



Gelatine plates — On gelatine 

 plates colonies appear first as white 

 points, developing later into delicate 

 stellate colonies, which eventually 

 coalesce and form a fine mycelial 

 network covering the surface of the 

 medium. 



Agar plates — Growth similar to 

 that on gelatine. 



Non-pathogemc. 



